Metropolitan planning organizations (MPO) and air quality management districts (AQMD)
are looking to transportation control measures (TCM) for solutions to worsening traffic
and troublesome air pollution. TCMs come in many forms, from reducing driving by
increasing its cost, to better transit, to trip-shortening land use changes, to employer
efforts, to reducing emissions by lowering emission limits or improving traffic flow.

To judge this wealth of options, we must understand why Americans drive so much, if we
really do. Table 1 compares VMT/capita for seven developed countries. Americans average
nearly four times as much driving as the Japanese do, and about twice that of the most
developed European countries. Why do we drive so much more than others with incomes
similar to ours?

I want to suggest that there are three major reasons Americans drive more than our
peers in Europe and Japan. First, we heavily subsidize auto and truck use. Very credible
studies--by Charles Komanoff and Brian Ketcham, by the Natural Resources Defense Council,
by the World Resources Institute, by the city of Boulder CO, and even by the Office of
Technology Assessment, an arm of Congress--calculate total subsidies of $3.00 to $7.00 per
gallon of gas.1 Every time we pump in a $1.25 gallon of gas we also pump in $3 to $7 in
subsidies. These studies are summarized in Table 2.

Where do these subsidies occur? They include the costs of road repair, policing and
motorist protection not paid for by the gas tax; "free" parking; uninsured
accidents; noise; vibration damage; pollution damage to human health, crops and
structures; global warming; petroleum subsidies; policing the petroleum supply line, or
wars in the Mid-East; and congestion. Non-drivers subsidize driving when they pay income,
sales, property and other taxes used for parking, roads, health care and fighting wars.
They subsidize drivers through health or other costs of pollution, or when goods or
services include free parking or higher worker health care. Even when drivers pay some of
these subsidies, their costs are not directly related to how much they drive, and so are
not incentives to drive less. We could take cars off welfare by charging the full cost of
parking, increasing gas taxes, instituting pay-at-the-pump insurance, smog fees and
congestion pricing on roads. These smell suspiciously like some widely-proposed TCMs.

Public transit is inadequate and deteriorated

Second, we have allowed our public transit systems to deteriorate and be
dismantled. Notable was the conspiracy of auto and tire manufacturers and oil companies,
under the guise of National City Lines, to buy up and dismantle public transit lines all
over the country.2 But state and local governments also participated in dismantling public
transit. Meanwhile we spent trillions of public dollars building interstates and other
highways. New roads, and the perception that they will reduce traffic congestion, lure
people to locate farther from their jobs and shopping.

Congress' 1991 surface transportation act, Intermodal Surface Transportation Efficiency
Act (ISTEA), brought a promise of increased spending flexibility between roads and
transit. How is that promise being fulfilled? Metropolitan planning organizations and
state departments of transportation nationwide are still directing most funds to the same
old road projects--an absence of vision on their parts.

Look at how MPOs could forge transit into effective TCMs. They could develop regional
transit visions with regional rail networks--modern heavy or light rail systems joining
the major urban centers with each other and with major residential areas. Rail, because it
is visible and elegant, attracts more support and riders. People better visualize transit
routes when they see its tracks. The route's permanence attracts investment in infill
housing and commerce, increasing ridership. Feeding these rail systems would be bus
networks. State DOTs could develop high speed rail to connect urban areas. Improved public
transit could be a very effective TCM.

Many Communities are unwalkable

Third, we have built communities hostile to pedestrians, bicyclists and transit
users. Sprawl, now so common, lengthens distances to destination and to transit. Patronage
and revenues decline. Expanding routes to provide service within walking distance raises
expenses, so service deteriorates. Pedestrian-oriented cities have much higher levels of
transit use.

How can we forge communities accessible by foot, bicycle and transit? There are three
simple steps. First, increase the density, especially around transit, to multiply the
destinations within reach. Second, locate residences, jobs, markets, restaurants, et al
close together. Living in the Russian-Nob Hill-Chinatown-North Beach area of northeast San
Francisco, I have over 700 restaurants within one mile, an easy and inviting walk, and
probably as many food markets. Many of these are corner or mid-block stores on residential
streets. Even in less dense neighborhoods these businesses should be located on major
streets in the neighborhoods, not stuck off in shopping centers 5 miles away, accessible
only by driving.

Finally, design a friendly pedestrian environment, including an efficient pedestrian
street grid not broken by dead ends or split by freeways or drainage ditches. Include wide
sidewalks, bus shelters, sidewalk furniture and weather protection, convenient building
entrances and safe traffic. These three steps improve accessibility to your destinations
and to transit: density, mixed-use and pedestrian-friendly.

Now, these are not surprising revelations. Most of you sense this to be true. You've
walked through traditional villages crowded with walkers--carrying out their businesses or
just enjoying themselves. The sidewalks were wide and inviting. The stores, restaurants
and coffee houses were varied, friendly and eye-catching. A mile walk there seemed like a
short trip. You loved it, whether this village was a small town, or Greenwich Village, the
Loop, North Beach or Chinatown.

Can we prove pedestrian/transit cities really work?

Do we have proof that pedestrian/transit actually reduce driving? We scientists
always want numbers. In a couple studies for the Natural Resources Defense Council (NRDC),
I analyzed communities in the San Francisco region which varied from high density
northeast San Francisco, where I live, to low density suburbs like San Ramon.3 The second
study included communities in Los Angeles, San Diego and Sacramento. I found that high
residential density, nearby shopping, good transit and a good walking environment go
together. And, alternatively, sprawling suburbs isolate stores into shopping centers, have
poor transit service, and often don't even have sidewalks.

I found that residents of the higher density communities do drive substantially less.
Comparing the extremes, northeast San Francisco was found to have 32 times higher
household density, and 200 times higher local serving job density than San Ramon, while
its residents had only about 1/4 the household auto ownership and VMT. Both studies found
that, on average, we drive 20 to 30 percent less per capita or per household than
residents of an area half as dense. In other words, if you live in a neighborhood with
twice the density of your sister's, on average you will drive 20 to 30% less than she and
her neighbors. This general relationship of density to auto use was also found in New
York, Chicago, Toronto and British cities.

The basic question for planners is--what do we really want to accomplish: moving more
vehicles--which planners term mobility, or facilitating people getting to their
destinations--which we call accessibility? If you can walk to the market or telecommute to
work you have accessibility but no mobility! Aren't we now providing mobility,
albeit often congested mobility, to those with cars, and denying it to those who can't
afford cars, or are young or old, or who just don't want to drive? Wouldn't TCMs which
give accessibility without moving so many cars be effective, and more equitable? There are
TCMs that decrease driving and congestion while increasing accessibility.

Employee Trip Reduction Ordinances

But wait, how are air quality agencies and transportation planners attacking
excessive driving? With Employee Trip Reduction Ordinances (TRO)! Yeah, ask the employer
to solve the problem, even though only one-fourth of trips are work trips, yielding
one-third of total VMT. Actually, there is some sense to this requirement, since
congestion is worst during commute hours and one goal is to reduce congestion, as well as
the extra pollution from stop-and-go traffic. Also, non-driving employees are less likely
to make drive-alone trips at noon.

The 1990 Clean Air Act Amendments require Employee Commute Options (ECO) in the twelve
most polluted regions of the country. The California Clean Air Act requires air quality
agencies in the most polluted air basins to enact local ordinances designed to achieve an
Average Vehicle Ridership (AVR) of 1.5 for commute trips. Hence, the South Coast Air
Quality Management District's infamous Reg. XV. It requires employers to develop a plan to
achieve this at each work site with 100 or more morning commuters. Get this--it doesn't
require achieving 1.5, only developing plans and making efforts to achieve it.

Less polluted basins, like the San Francisco area, must enact local ordinances designed
to achieve an AVR of 1.4 for commute trips. Like Reg. XV, the Bay Area Air Quality
Management District's Reg. 13 only requires preparation and implementation of employer
plans. To achieve a regionwide AVR of 1.4, the BAAQMD divided the region into four zones,
as shown on Figure 1. Downtown San Francisco has to achieve an AVR of 2.5 by 1999; the
rest of San Francisco and downtown Oakland and Berkeley must achieve 1.5; the rest of
Alameda county, along with San Mateo, Santa Clara and Contra Costa must achieve 1.35;
while the northern counties of Marin, Sonoma, Napa and Solano only have to meet 1.3. Even
then, some suburban employers came to the air district complaining "we chose to
locate our sites out in the boonies where land is cheap, but there is no transit nor
nearby housing so let us off the hook! Lower our goals even more." That's probably
not exactly the way they phrased it, but that's what I heard.

As you can see, the bulk of the effort is loaded on downtown San Francisco. Already one
county meets its 1999 goal, so its employers don't have to prepare TRO plans. Which
county? San Francisco! This demonstrates the effectiveness of higher densities, good local
shopping, pedestrian-oriented streets, good transit, and limited downtown parking!

TCM effectiveness

Let's look at the whole spectrum of TCMs. For discussion, I'll classify them as market-based,
land use, pedestrian/bicycle/transit, traffic improvements and telephone-based,
as shown in Table 3.

We have predictions of TCM effectiveness for four major urban regions: San Francisco,
Los Angeles, Washington DC and New York City. We usually measure effectiveness by VMT
reductions. Since cold engines (cold starts) emit more pollutants than hot ones, vehicle
trips (VT) are also important. However, VMT is the universally reported measure of
effectiveness. These predictions are based on measured or estimated responses of travelers
to increases or decreases in travel costs or time.

These predictions include immediate responses to changed travel conditions and
secondary impacts--as when the reduced traffic following a gas tax increase lures others
to drive. But these predictions do not adequately model the longer-term reductions
resulting from densification, or people moving or changing employment locations to take
advantage of improved transit. Or the synergism among some TCMs, yielding even more VMT
reductions than indicated for each one acting alone. For instance, mixed-use infill
development, pedestrian and transit improvements, and barriers to parking might give
greater reductions than simply adding the effects of each acting alone.

While the predictions vary between regions, general conclusions can be drawn. Sharp
reductions in VMT can be achieved by market-based TCMs, land use changes or achieved
pedestrian/bicycle/transit improvements. The greatest short-term reductions in VMT are by
the strongest market-based measures. But is it reasonable to talk about a $2 gasoline tax?

Figure 2 shows gasoline taxes and prices in the U.S., Canada, many European countries
and Japan. $2 gas taxes are common elsewhere.

A combination of land use and pedestrian/bicycle/transit improvements can give
substantial reductions. Traffic improvements can actually increase VMT, however, as
driving increases to take advantage of reduced congestion. Telecommuting might reduce rush
hour commutes, but may free up employees for more mid-day trips.

In addition to these TCMs, efforts to clean up auto emissions by tightening emissions
limits on new cars and inspection & maintenance of operating vehicles are sometimes
thought of as TCMs with statewide or nationwide implementation.

Testing an integrated package of TCMs

How would you test the effectiveness of a package of TCMs? We analysts say
"Pay us to model it on the computer." The San Francisco bay area's MPO, the
Metropolitan Transportation Commission (MTC), put their analysts to work doing that. They
tested an integrated package of TCMs for the Regional Alliance For Transit (RAFT) -- a
transit and environmental coalition. RAFT defined a pedestrian- and transit-oriented
projection for MTC to analyze as a part of the development of the 20-year Regional
Transportation Plan (RTP).

RAFT specified a year 2010 transportation system which eliminated nearly all of MTC's
500 new highway lane-miles, and put the savings into cost-effective public transit.
It stressed rail improvements in the urban corridors, including CalTrain from San Jose to
San Francisco's downtown Transbay Terminal, light rail in San Francisco and Santa Clara
counties, heavy rail on existing tracks to link Santa Clara light rail to East Bay BART
and on to Livermore, Sacramento and San Joaquin county, and commuter rail in Marin and
Sonoma counties. RAFT also included electric trolley-buses in the East Bay urban corridor
between Hayward, Oakland and Richmond, and express buses on I-80 and I-680. Having
improved CalTrain service to San Francisco Airport, RAFT eliminated the parallel, more
expensive, BART extension. RAFT converted some freeway lanes to bus/carpool lanes.

RAFT included only one market-based measure: parking cash-out, whereby
non-driving employees receive the cash value of their unused "free" parking
space. This was the only market measure that could be implemented immediately, without
changes in state law or a vote of the electorate. California law allows county congestion
management agencies to mandate such parking cash-out.

RAFT assumed the same total regional population and job growth as MTC, but clustered
the growth of households and employment after 1995 around transit stations. It saved
some 200 square miles of forests, grasslands and farmlands that MTC's alternative would
have developed for residences, commerce, industry and local streets. By developing in
areas mostly supplied with infrastructure -- schools, public facilities, streets and
utilities, the region could save the $25 billion cost of new facilities.5

You can see how effective this package of TCMs would be. And this package doesn't
include the many market-based measures that local authorities now lack the authority to
implement. The potential to utilize TCMs to improve our lives and our air quality is
there, given political courage and leadership.

TCM Recommendations

Adding these studies up, what conclusions can we draw? Make sure that your region
considers and evaluates a full spectrum of potential TCMs. Forge an integrated package of
TCMs that is effective in reducing VMT. That package should include:

strong market measures to reduce or eliminate subsidies to driving and increase the
per-mile and per-trip cost of driving;

strict limits on highway capacity increases, with perhaps some strategic reductions in
capacity;

zoning, financial incentives and public education to encourage higher density, mixed-use
development near transit stations and in transit corridors; and

pedestrian and bicycle improvements to increase the pleasure or walking and riding in
neighborhoods.

Moreover, be very cautious about TCMs that would change signal timing, intersection
reconfiguration or other changes to speed traffic. While smoother traffic pollutes less,
it can drive VMT up as drivers move farther from work to take advantage of decreased
commute times, etc. This could swamp the smoother flow effects. And the faster traffic
threatens pedestrians and bicyclists.

Transportation Control Measures, writ large, can be a very effective tool for improving
our urban areas, decreasing traffic and improving air quality. You can help your community
to use them effectively.

A colleague of mine urged me to address another reason we drive so much--our "car
culture". Americans are felt to be one with their cars, inseparable. A person without
a car is not really a person. Mention cars and we picture ourselves tooling along an empty
country road, as depicted in TV ads. This image obscures reality. The normal experiences
of most Americans is stuck in traffic. As auto ownership and VMT expand this congestion
will get worse. Yet, the $4.5 billion auto manufacturers annually pump into ads keeps this
idealized image vibrant and autos seemingly essential to our quality of life. How do we
address this problem? Will exposing us to the magnitude of our subsidies to cars, and the
harm cars do to the environment, our cities and our accessibility smudge the glossy image
of cars?

5. Using per acre mixed suburban infrastructure costs, in 1994 dollars, from Real
Estate Research Corporation, The Costs of Sprawl: Detailed Cost Analysis, U.S.
G.P.O. Stock Number 4111-00021, Council on Environmental Quality, Department of Housing
and Urban Development, and the Environmental Protection Agency, Washington DC, April 1974.